Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a medium bowl, combine softened cream cheese, shredded cheddar cheese, garlic powder, and onion powder until well mixed.
Fill each jalapeño half with approximately 1 tablespoon of the cheese mixture, smoothing the top.
Wrap 2 to 3 strips of prosciutto around each stuffed jalapeño in a staggered fashion, leaving a small gap near the top for the eyes.
Place the wrapped peppers on the prepared baking sheet.
Bake for 12 to 15 minutes or until the prosciutto is slightly crisp and the peppers are tender.
Remove from oven and immediately press two olive slices into the cheese gap of each pepper to create mummy eyes.
Allow to cool for 5 minutes before serving to let the cheese set.